TY - JOUR T1 - METABOLISM OF NIFLUMIC ACID-<sup>14</sup>C: ABSORPTION, EXCRETION AND BIOTRANSFORMATION BY HUMAN AND DOG JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 323 LP - 330 VL - 186 IS - 2 AU - S. J. LAN AU - T. J. CHANDO AU - I. WELIKY AU - E. C. SCHREIBER Y1 - 1973/08/01 UR - http://jpet.aspetjournals.org/content/186/2/323.abstract N2 - The metabolism of niflumic acid-14C was studied in humans and dogs. In both species, it was quickly absorbed, metabolized and excreted after oral administration. Peak levels of niflumic acid in plasma were reached within 2 to 3 hours after the dose, and only traces of niflumic acid were found in plasma after 24 hours. A direct relationship was found between the disappearance of niflumic acid-14C and the appearance of metabolites in the plasma. After oral administration of a capsule containing 250 mg of 14C-labeled niflumic acid, human subjects excreted 40% of the radioactivity in urine within 48 hours and 30% in feces within 72 hours. Dogs given a dose of time labeled drug. 10 mg/kg, either p.o. or i.v., excreted 20% of time radioactivity in urine and 80% in feces. More than 75% of time radioactivity excreted in urine and 25 to 50% of that in feces occurred as conjugates with glucuronic acid or as sulfate esters. The major metaboiites in urine and feces from both species were isolated and identified as niflumic acid glucoronide, 4'-hydroxyniflumic acid, 5-hydroxyniflumic acid and the glucuronide and sulfate conjugates of 4'-hydroxyniflumic acid and 5-hydroxyniflumic acid. © 1973 by The Williams &amp; Wilkins Co. ER -